1997 ifor Williams 510 - how much?

It has a wooden floor which is in ok but not perfect condition and will need replaced, one hinge needs replaced on jockey door and rear 1/2 door. Brakes recently done and new tyres all round. Has a little wear and tear to the internal padding but otherwise in good condition. Trailer belongs to a friend and I want to offer him a fair price, but all he'll tell me is he was going to sell at auction with a reserve of £600.

Well I have a 1997 505 with an alloy floor I had put in 10 years ago. What are the outside panels like? I've had to re do the front ramp this year and the near side panel which is original will need replacing soon also the back ramp. Look at the bottoms of the panels, that's where you'll most likely see the softening. Wear and tear on the interior is less important so long as it's still safe and functional. It's also amazing what you can do with a staple gun. I think a fair price for one of this age with everything up and together and in good nick for a 20 year old trailer (with alloy floor) would be £1500-1800 for a 505 so a bit more for a 510. Check the panels and then decide. Would he let you have it for £750?